This invention relates to an ammonia-free composition for colouring keratinous fibres.
It also relates to a method for colouring fibres, and in particular hair fibres.
The only methods for colouring hair able to cover the hair completely and durably are the methods of colouring by oxidation which lead to colourations known as permanent colourations.
During the oxidation reaction used in these methods, the colouring precursors, which are aromatic compounds belonging to the families of the diamines, amino phenols (or amino naphthols) and phenols (or naphthols), are oxidized in the presence of hydrogen peroxide and an alkaline base, preferably ammonia.
In a first step, these precursors are converted into highly reactive radical intermediates which couple between themselves to form, during the second step of the oxidative reaction, coloured polymers which can firmly fix into the keratinous fibre.
Until recent years, permanent colouring was performed in strong oxidizing alkaline conditions, in other words with high concentrations of hydrogen peroxide (generally 3%) in the final mixture and in the presence of a strong base such as ammonia to alkalize the medium (pH close to 11).
In this type of reaction, the hydrogen peroxide has two functions: to decolorize the existing pigments so as to avoid variations in colour resulting from the initial colour of the hair, and to initiate the oxidative process of the colouring agents.
The ammonia improves the dissolution of the colouring agents, and, by alkalinization of the medium, promotes the discolouration action of the peroxide by releasing active oxygen.
As a strong base, the ammonia also acts on the swelling of the fibre by causing opening of the scales. It thus promotes the penetration of the colouring precursors and ensures even distribution of the pigments as far as the core of the fibre.
This permanent colouring technique has always given excellent results, from the points of view of the coverage of white hairs (close to 100%), the range of shades available, and the resistance to washing of the colouration obtained. In fact, this type of colouring, which irreversibly changes the pigmentation of the hair, is very resistant to repeated shampooing.
Despite its good performance, this technique has several disadvantages, mainly resulting from the strong oxidizing alkaline conditions.
In frequent and repeated use, it can cause physico-chemical degradation of the fibre and irritate sensitive scalps. In the long term, the hair can become dry and harsh to the touch, and lose its softness and natural brilliance.
The applications must be renewed because the growth of the fibres in their original colour leads to an unattractive dividing line between the uncoloured and coloured sections. This appearance of uncoloured hair roots is often very unsightly and requires frequent corrective applications.
Ammonia is a highly volatile strong base which releases a disagreeable and stifling odour during the preparation of the product and its application. In addition, on the industrial scale, the evaporation of the ammonia involves problems in retaining a constant level of alkalinity during the manufacture of the product.
For this reason, new oxidation colouring compositions called xe2x80x9ctone on tonexe2x80x9d, which are semi-permanent and non-lightening, have appeared on the market in recent years. These new types of colouration use the same colouring precursors as the conventional oxidation colouring, but very often ammonia is replaced by monoethanolamine or aminomethylpropanol, and the peroxide concentration of the oxidant is approximately half reduced.
These colourations aim at young women aged from 25 to 40, who have a low percentage of white hairs, and seek natural shades or xe2x80x9cfashionsxe2x80x9d covering their original colour transparently, without the appearance of uncoloured roots and without damaging their scalps. These new formulae are in fact very attractive for this type of customer who do not wish an irreversible permanent colouration.
However, these mild colourations with very attractive qualities do not offer the colouration efficiency of the conventional ammonia colourations, in particular regarding their coverage of white hairs and their resistance to shampooing. The alkaline bases selected cause less swelling of the hair than ammonia and the colouring agents are localized mainly in the cuticle and the outside of the cortex, and only rarely in the core of the fibre. This different penetration of the colouring agents in the fibre results in colourations which only cover 50% of white hairs and which only last for about ten washings. As they are non-lightening, they can only be used as a tone on tone colour to revive or deepen the natural colour, or to add highlights.
High concentrations of acrylic-itaconic copolymers are used as thickening agents in colouration compositions. Acrylic-dimethyldiallylammonium chloride copolymer is used in shampoo formulations. However, compositions containing these two compounds are not known.
It thus emerges from the prior art that there is no method for effective hair colouration which gives good coverage and resistance but which does not lead to problems in use.
The applicant has shown that it is possible to obtain such a colouration by using a ternary complex in the colouration compositions.
The object of the present invention is thus an ammonia-free composition for colouring keratinous fibres, and in particular hair, comprising an oxidant compound, colouring precursors and a non-volatile and odourless alkalizing agent, characterized in that it further comprises:
a quaternized copolymer of dimethyldiallylammonium and acrylic acid, subsequently referred to as quaternized polymer,
a quaternized silicone, and
an acrylic-itaconic copolymer esterified by one or more fatty alcohols, optionally polyoxyethylenated.
The quaternized copolymer, the quaternized silicone and the acrylic-itaconic copolymer advantageously form a complex within the composition. This ternary complex itself is an object of the present invention.
The quaternized copolymer of dimethyldiallylammonium and acrylic acid may correspond to formula I in the annexe, in which x may be between 1 and 1000, preferably between 1 and 100, and y and z may independently be between 0 and 1000, preferably between 0 and 100.
Except where otherwise stated, all the quantities of the components of the composition are expressed in percentage by weight.
The quaternized polymer is preferably a poly quaternium, such as polyquaternium-22 or polyquaternium-39. These compounds may be present at concentrations of between 0.1 and 1.5% by weight of the composition. A composition according to the present invention advantageously contains from 0.5 to 1% by weight of polyquaternium-22.
The quaternized silicone may be a polyquaternized polydimethylsiloxane corresponding to formula II in the annexe, in which R1 represents a C6 to C20 alkyl group and n is between 1 and 1000, preferably between 1 and 100, such as a diquaternized polydimethylsiloxane. The R1 group advantageously represents one or more alkyl groups derived from coconut oil. These quaternized silicones may comprise between 0.02 and 0.5% by weight of the composition and preferably from 0.05 to 0.25% by weight.
The acrylic-itaconic copolymer is advantageously substituted with one or more C6 to C20 alkyl groups, of which at least one is polyoxyethylenated, and corresponds to the general formula III in the annexe, in which R2 and Rxe2x80x22 represent alkyl groups, xxe2x80x2, yxe2x80x2 and zxe2x80x2 are integers between 1 and 1000 and preferably between 1 and 100, and nxe2x80x2 is between 1 and 100, preferably between 10 and 30, and even more preferably is 20.
R2 preferably represents an acrylic and/or methacrylic acid ester, in particular an ethyl, butyl or methyl ester and Rxe2x80x22 a stearyl or cetyl radical.
Such copolymers advantageously have a molecular weight of between 105 and 107, and preferably close to 106.
The concentration of acrylic-itaconic copolymer may be between about 0.1 and 10% by weight of the composition. Such a copolymer is preferably composed of a mixture of acrylate-steareth-20 or ceteth-20-itaconate copolymers, in quantities of between 0.3 and 4% by weight of the composition.
The composition according to the present invention may thus contain between 0.2 and 12% by weight, and preferably between 0.8 and 5% by weight of the ternary complex formed by the three compounds identified above.
The three components of the complex are advantageously present in quantities suitable for obtaining a synergetic effect. These quantities correspond to the preferred ranges stated above.
The composition according to the present invention particularly advantageously comprises at least:
between about 0.1 and 1.5% by weight of a quaternized copolymer,
between about 0.02 and 0.5% by weight of a quaternized silicone,
between about 0.1 and 10% by weight of an acrylic-itaconic copolymer,
between about 0.75% and 6% by weight of an oxidant compound,
between 0.5% and 10% by weight of colouring precursors, and
a quantity of an alkalizing agent sufficient to give a pH of between about 7 and 11.
The composition according to the invention may in addition contain between 2 and 30%, and advantageously between 10 and 25% by weight of an alcohol or a mixture of alcohols preferably from C2 to C8, such as ethanol, propanol or isopropanol.
The colouring precursors comprise the bases and the couplers.
The bases or primary intermediates may be aromatic amines, diamino phenols or amino phenols whose NH2 and OH groups are in ortho or para positions with respect to each other. They are responsible for the deep shades and can couple to each other to form highly coloured pigments.
They may in particular be para-phenylenediamine (pPD), ortho-aminophenol (oAP), para-methylaminophenol (pMAP), para-aminophenol (pAP), para-toluylenediamine (pTD) and/or N-phenyl-para-phenylenediamine (NpPD).
The couplers or modifiers may be meta-diamines, meta-aminophenols, polyphenols or naphthols. Taken alone or coupled between themselves, they give only a weak colouration; when coupled with a base, they modify the shade.
They may in particular be meta-aminophenol (mAP), resorcinol (R), 1-naphthol (1-N), meta-phenylenediamine (mPD), para-aminoorthocresol (pAOC) hydroquinone (Hq), 1,5-dihydroxynaphthalene (1.5 DHN) and/or 2,7-dihydroxynaphthalene (2.7 DHN).
The whole formulation must be suitable for the desired colouration result. Multiple base-coupler combinations are most often used.
It is also possible to obtain very light shades (platinum) by increasing the concentration of peroxide and alkalizing agent, as a function of the original shade.
The total quantities of these molecules are comprised in a range of between 0.5% and 10% by weight of the composition and advantageously of about 2%.
The composition preferably contains from 1 to 30% by weight of an alkalizing agent, which may in particular be aminomethylpropanol, monoethanolamine, diethanolamine, triethanolamine, or their mixtures, and preferably from 5 to 20% of monoethanolamine.
The composition may in addition contain various additives normally used in oxidation colouration. These additives may be oxyethylenated or polyglycerolated natural or synthetic fatty amines; oxyethylenated or polyglycerolated natural or synthetic fatty alcohols; anionic, non-ionic, cationic or amphoteric surfactants; solvents, sequestrants and perfumes.
The oxyethylenated fatty amines used may be tertiary amines composed of an alkyl group derived from fatty acids with 12 to 18 carbon atoms, and two polyoxyethylenated groups attached to the nitrogen atom. These fatty amines may be used at concentrations from 5 to 20% and preferably from 10 to 20%.
The oxyethylenated or polyglycerolated natural or synthetic fatty alcohols used may be oleic, lauric, myristic, cetyl or stearyl alcohol. These fatty alcohols may be used at concentrations from 1 to 25%, and preferably from 3 to 15%.
The surfactants used may be anionic, non-ionic, cationic or amphoteric surfactants. They may be used at concentrations from 2 to 20%, and preferably from 5 to 15%.
The solvents, which may be used alone or in mixtures, may be ethyl alcohol, propyl alcohol or isopropyl alcohol and glycols such as propylene glycol, diethylene glycol, butyl glycol, hexylene glycol and diethylene glycol monoethyl ether. They may be used in concentrations from 5 to 30%, and preferably from 10 to 20%.
The pH of the composition may be between 7 and 11 and preferably between 8.5 and 10.5.
The colouration composition according to the invention is conventionally obtained by addition of an oxidant to the remainder of the components in a weight ratio of 1:1. The oxidant may in particular be a hydrogen peroxide solution of concentration between 1.5 and 12%, preferably between 6 and 9%, in which case the final concentration in the composition is between 0.75 and 6%, and preferably between 3 and 4.5%.
Despite the absence of ammonia, this composition colours hair with better coverage and fastness than those of known compositions. It combines the mildness and comfort of an ammonia-free colouration with colouring results comparable to those of a permanent colouration using ammonia.
This composition thus avoids the disadvantages associated with the presence of ammonia and covers white hairs completely and durably. The colourations cover the white hairs at a level close to 100%, without overload on the sensitive areas, and show good stability to washing. The composition according to the invention offers natural shades. The highlights are deeper on the day of the colouration and do not lose their brightness after shampooing.
It may be hypothesized, but without being linked by any theory, that the formed complex improves the lasting fixation of the colouring agents in the fibre. In addition, the cationic components of this composition should have a protective action during the oxidative reaction and a surface conditioning effect on the fibres.
Protected by this composition, the hair after colouration retains a soft and silky feel. It keeps the softness, firmness, elasticity and brilliance of healthy hair. The composition also improves the combing and styling of the hair after treatment.
It in addition causes no adverse reaction to the scalps of the majority of the individuals treated.
The composition according to the present invention may be in the form of a liquid, a gel, a gellable liquid or a cream.
However, gellable compositions are preferred for their ease of application and the luminosity of the shades obtained.
The gellable liquids may be prepared either from polyoxyethylenated or polyglycerolated non-ionic compounds and solvents, or from liquid fatty acid soaps and solvents.
A further advantage of the composition according to the present invention lies in the possibility of avoiding the use of polyoxyethylenated alkyl phenols in the medium for forming a gel by dilution. These gelling compounds, widely used in this type of composition in the past, are now considered as poorly biodegradable and toxic to aquatic life. They may have a hormone-like activity which could interfere with the development of river fauna, and are currently threatened with prohibition.
Mixing the colouration medium with the oxidant solution containing the hydrogen peroxide in the defined dilution ratios gives a gel which may readily be applied to the hair.
The composition which is the object of the present invention may be produced by mixing, in a manner known to a person skilled in the art, of the different components which it contains.
It is preferably prepared by mixing an alcoholic solution comprising at least:
a quaternized silicone,
a quaternized copolymer of dimethyldiallylammonium and acrylic acid,
the colouring precursors, and
an alkalizing agent, with a solution containing at least:
an acrylic-itaconic copolymer, and
an oxidizing agent.
These solutions comprise in themselves objects of the present application.
The composition according to the present invention may be used in a method for colouring keratinous fibres, and in particular hair fibres, comprising the following steps:
application of the composition to said fibres, for a length of time sufficient to obtain the desired colouration, and
rinsing and drying the fibres.